I have the WH-1000XM2 and they're still pretty good overall.
The thing is, I haven't seen any way in which I can purchase original replacement ear pads or a battery.
Any authorised Sony service agent should be able to get genuine parts for you. They're not exactly cheap, though, be warned!
Here's the battery for the XM2, for example. A set of ear pads costs about the same.
Sony LITHIUM ION BATTERY PACK(SP73), 185367611 - EET Europarts UK
Buy online Sony LITHIUM ION BATTERY PACK(SP73), 185367611 in stock and delivered quickly at good price
